An example of an image forming apparatus, such as a laser printer, has a cleaning roller for removing deposited matter, such as residual toner and paper dust, on the circumferential surface of a photosensitive drum. The cleaning roller is disposed such that the circumferential surface thereof is in contact with the circumferential surface of the photosensitive drum. The cleaning roller is rotated such that the contact portion with respect to the circumferential surface of the photosensitive drum is moved in the same direction as the moving direction of the circumferential surface of the photosensitive drum.
A driving force for rotating the cleaning roller is transmitted from the photosensitive drum. That is, a drum gear rotated together with the photosensitive drum is provided at an end of the photosensitive drum. Further, a cleaning gear rotated together with the cleaning roller is provided at an end of the cleaning roller. The cleaning gear meshes with the drum gear. When a driving force is input to the photosensitive drum, the photosensitive drum is rotated, and the driving force is transmitted from the drum gear to the cleaning gear. Thus, the cleaning roller is rotated.
However, because the drum gear meshes with the cleaning gear, the rotation speed of the drum gear and, therefore, the photosensitive drum may vary due to the meshing conditions or the like, which may result in banding (a banded pattern developed on an image due to uneven density).